ACP adapter for pi coding agent
npm install pi-acpACP (Agent Client Protocol) adapter for pi coding agent (fka shitty coding agent).
pi-acp communicates ACP JSON-RPC 2.0 over stdio to an ACP client (e.g. an editor) and spawns pi --mode rpc, bridging requests/events between the two.
This is an MVP-style adapter intended to be useful today and easy to iterate on. It intentionally leaves some ACP features unimplemented (see Limitations).
- ACP side: JSON-RPC 2.0 over stdio using @agentclientprotocol/sdk
- Pi side: spawns pi --mode rpc and communicates via newline-delimited JSON on stdio
- Session model: 1 ACP session ↔ 1 pi subprocess
High-level mapping:
- session/new → spawn pi --mode rpc (working directory = cwd)
- session/prompt → send { type: "prompt", message, attachments } to pi and stream events back as session/update
- session/cancel → send { type: "abort" }
- Streams assistant output as ACP agent_message_chunk
- Maps pi tool execution to ACP tool_call / tool_call_update
- For edit, pi-acp snapshots the file before the tool runs and emits an ACP structured diff (oldText/newText) on completion when possible
- Session persistence
- pi stores its own sessions in ~/.pi/agent/sessions/...
- pi-acp stores a small mapping file at ~/.pi/pi-acp/session-map.json so session/load can reattach to a previous pi session file
- Slash commands
- Loads file-based slash commands compatible with pi’s conventions
- Adds a small set of built-in commands for headless/editor usage
- Skills are loaded by pi directly and are available in acp sessions
Make sure pi is installed
``bash`
npm install -g @mariozechner/pi-coding-agent
- Node.js 22+
- pi installed and available on your PATH (the adapter runs the pi executable)pi
- Configure separately for your model providers/API keys
Add the following to your Zed settngs.json:
#### Using with npx (no global install needed):
`json`
"agent_servers": {
"pi": {
"type": "custom",
"command": "npx",
"args": ["-y", "pi-acp"],
"env": {},
},
},
#### Global install
`bash`
npm install -g pi-acp
`json`
"agent_servers": {
"pi": {
"type": "custom",
"command": "pi-acp",
"args": [],
"env": {},
},
},
#### From source
`bash`
npm install
npm run build
Point your ACP client to the built dist/index.js:
`json`
"agent_servers": {
"pi": {
"type": "custom",
"command": "node",
"args": ["/path/to/pi-acp/dist/index.js"],
"env": {},
},
},
pi-acp supports slash commands:
#### 1) File-based commands (compatible with pi)
Loaded from:
- User commands: ~/.pi/agent/commands/*/.md
- Project commands:
These are expanded adapter-side (pi RPC mode doesn’t expand them).
#### 2) Built-in commands
- /compact [instructions...] – run pi compaction (optionally with custom instructions)/autocompact on|off|toggle
- – toggle automatic compaction/export
- – export the current session to HTML in the session cwd
- – show session stats (tokens/messages/cost/session file)/queue all|one-at-a-time
- – set pi queue mode (unstable feature)/changelog
- – print the installed pi changelog (best-effort)
Other built-in commands:
- /model - maps to model selector in Zed/thinking
- - maps to 'mode' selector in Zed/clear
- - not implemented (use ACP client 'new' command)
The rest are not yet implemented due to ACP limitations (e.g. no history)
`bash`
npm install
npm run dev # run from src via tsx
npm run build
npm run lint
npm test
Project layout:
- src/acp/* – ACP server + translation layersrc/pi-rpc/*
- – pi subprocess wrapper (RPC protocol)
- No ACP filesystem delegation (fs/) and no ACP terminal delegation (terminal/). pi reads/writes and executes locally.agent_message_chunk
- MCP servers are accepted in ACP params and stored in session state, but not wired through to pi.
- Assistant streaming is currently sent as (no separate thought stream).one-at-a-time
- Queue is implemented client-side and should work like pi's
- ACP clients don't yet suport session history, but ACP sessions from can be /resume`d in pi directly
MIT (see LICENSE).